Any one understand horn circuit?

[mrgrim]

I need help with the horn in my 88 K5. It is stuck on and neither of the repair manuals I have cover it. The problem is in the steering wheel. If you pop off the horn pad that says GMC or Chevrolet there is a metal cup with 3 screws in it. The horn pad clips into it and that is what holds the pad in place. If I remove that cup and the thin plate behind it the horn stops. Would any one have pictures or know how it should be assembled? I dont know if some thing
is out of order and is touching some thing or if some thing is just worn out.
I need to get the thing inspected and I cant seem to figure this out.
Any help is very much appreciated.

I am offering a reward via paypal to the person who
helps to solve the problem!!!!

 

[thedrip]

As far as how the horn works, whats in the steering wheel is a very simply switch connected to ground. you press the button, it grounds the horn wire coming up the column to the column itself. that horn wire is attached to a relay, and it activates when grounded, then supplies 12v to the horn so it toots. Whats going on is your horn button is stuck "on". Either there is a missing spring that is supposed to hold the button out, or something is bent/misshapen and is always making the connection.

 

[British Slave]

Right below that thin plate should be a small contact. It is probably shorted. As I recall, the metal cup "rocks" on the thin plate, which then contacts the small contact and makes the horn blow. Pull that contact out and be sure the contact, spring and wire are in good condition. (disconnect battery or pull horn fuse first)
Make sure that the thin plate is not bent.

 

[mrgrim]

The spring and pin are in good shape. The problem is when you tighten up the 3 screws that hold the cup in place the horn comes on.It seems there should be a spring pushing the disk away from the spring and pin. Is there some kind of insulation thats missing in mine? It seems the 3 screws in the cup should have spacers or some thing.That would limit how close the disk and cup would be to the pin and spring when you tighten the 3 screws.

 

[TucsonK5]

Do you have the little plastic ring with holes for screws to go through to insulate them from the metal? Not the right year, but it would look like part #8 here: http://www.lmctruck.com/icatalog/cb/full.aspx?Page=137

 

[mrgrim]

No there is no plastic parts in there.... Where is it placed in the wheel?

 

[TucsonK5]

Basically the order is screw head, plastic ring, cup, spring plate (at least that's how mine is and it works). Mine is in a different order than the LMC diagram. The outer edge of the ring broke, but you can still see the remnants under the screw heads and between 9 and 12 o'clock positions.

 

[mrgrim]

Any idea where I can get one? Cause I sure don't have that in mine.

 

[British Slave]

That should be a dealer item.

 

[4X4HIGH]

Any idea where I can get one? Cause I sure don't have that in mine.

Cheap from your local wrecking yard. It will be thesame for any GM vehicle from 73-90 something at least.

 

[mrgrim]

I placed an order wit GMpartsdirect. Down side is each pack contains 10 pieces. So I am going to have spares.

 

[bp71k5]

I got mine from lmc. I imagine they also have the later years too.